Ok, enough is enough. No more snow dances, no more rain dances, no more cloud seeding. It’s time to turn to science and real live white-coat-wearing science performers to explain just what is going here this winter. As you know now, the lower 48 have experienced a joke of a winter so far and Meteorologists think they have figured out why the continental U.S. has been so warm and dry.
Just how bad has the 2011-12 winter been until now? The first week of January was the driest in history and more than 95% of the United States experienced below average snow cover, also a record portion of the country in this category. From January 2-8 more than 1,500 daily record high temperatures were set in the U.S.
The Scientific American is a publication that cannot be argued with for the words “science” and “American” are in the title; therefore, listen good and listen hard to what they explained and I am about to summarize. In the words of Mark Fischetti,
“The chief suspect behind the mysterious weather is an atmospheric pressure pattern called the Arctic Oscillation, which circles the high Northern Hemisphere. Its lower edge is known as the North Atlantic Oscillation (NAO). Together, the related features influence the path and strength of the jet stream. The jet itself is an air current that flows west to east across the northern latitudes of the U.S., Europe and Asia, altering temperature and precipitation as portions of it dip southward or crest northward.”
If the jet stream is strong and fairly straight then it acts as a barrier preventing cold arctic air from venturing south. This exact phenomenon has caused the warm and snowless winter that the continental U.S. has experienced so far. The jet stream is lingering very far north and has been for an uncharacteristically long time without many southward dips preventing,
“cold fronts from descending from the north and clashing with warm fronts, creating large snow and rainstorms” – Jeffrey Masters (Weather Underground)
You may have heard that the jet stream is to blame for your awful first half of winter, but now you know just how the jet stream blocks the storms you crave. Why these oscillations have had a tendency in recent years to fluctuate great distances however, meteorologists do not fully understand.
“The December Arctic Oscillation index has fluctuated wildly over the past six years, with the two most extreme positive and two most extreme negative values on record.” – Jeffrey Masters
Global warming and the associated loss of arctic sea ice has been charged with affecting the Arctic Oscillation and jet stream, but other theories are also in the mix to explain the despair of American Skiers.
Thankfully William Seward purchased Alaska in 1867, because now Americans have passportless access to Cordova and Valdez, both paces that are conveniently trapped under the jet stream and buried in snow. Educate yourself on this matter: unofficialnetworks.com/extreme-weather-alaska